Device for regulating electrical discharge



Aug. 17, 1948.

T. TOGNOLA ETAL DEVICE FOR REGULATING ELECTRICAL DISCHARGE Filed Dec.10, 1945 VII/147171111711 VII/111 101)!!! INVEN TURS.

ATTORNEY.

Patented Aug. 17, 1948 DEVICE FOR REGULATING ELECTRICAL DISCHARGE TullioTog-nola, Sidney, and Maurice S. Thorn,

Oneonta, N. Y., assignors to Bendix Aviation Corporation, New York, N.Y., a. corporation of Delaware Application December 10, 1945, Serial No.634,037

8 Claims. 1

This invention relates to a device for regulating electrical discharge.The problem of securing a uniform electrical discharge, for instanceacross an air gap, is quite difficult, particularly when the air gap issubjected to rapid and great variations in air pressure. Variousattempts have been made to combat this problem, but none has beenuniformly satisfactory.

The use of cold or hot tubes for regulating a discharge, the dischargedepending upon the ionization of gas within the tube, is known, but suchtubes are relatively complex in construction and generally require anauxiliary energizingcircuit for operation.

It is an object of this invention to control an electrical discharge bymeans which are independent of variations in air pressure. Anotherobject of the invention is to construct a cell ca pable of controllingan electrical discharge by means involving the ionization of a gas, allthe circuits of which are fed from a single electrode,

and the controlling action of which is inherent tures of the inventionwill more fully appear from the following detailed description when thesame is read in connection with the accompanying drawings. It is to beexpressly understood, however, that the drawings are for the purpose of2 cuit in which the cell is employed to regulate the discharge acrossthe spark gap.

Referring to Fig. l of the drawing, 10 represents a cylinder ofgas-impermeable dielectric material such as a dielectric plastic. Phenolformaldehyde plastics and hard rubber may be employed and are exemplaryof the useful materialsbutin the preferred form of the invention, thetube I0 is made of glass because of particu-lar advantages that arisefrom its use. 7

The ends of the glass tubev ID are sealed by metal plates I l and I2which arepreferably made of material having a coeflicient'of expansionclose to that of the glass tube, for example steel, Kovar nickel alloy,or nickel. These metal plates are a'ppliedto the ends of the glass andbecome sealed thereto when the glass is at red heat.

Itis advisable to put the parts under slight pressure while thefusingtakes place in order to insure the production of a tight joint. Theplates H and I2 carry stud electrodes l3 and I4 which maybeintegral-with the plate or attached theretoi by electricallyconducting means. For example, an electrode l3 of nickel may be welded,

' or silver soldered, to the plate. These electrodes are spaced fromthesides of the'tube l0. They are preferably fitted with caps l5, l6 oftungsten orlother hard and erosion resistant metal, the function .ofwhich is toprevent the swift disin tegration of the electrodes and toprevent the growth of deposits which tend to interfere with the"proper'functioning of the cell. The electrodes I 3 and I I are spacedfrom each other a distance'which is calculated in connection withthe'gas pressure and the imposed voltage to permit firing only'when adefinite potential is attainedin theanode. w

Spacing sleeves IT, I8 of insulating material such as glass, ceramic orthe like are provided within the cell and hold between them a metalcylind'er'Zfl which has a similar coemcient of expansionand may also befused to the glassin the same way asthe metal pieces at the. end. Thiscylinder has teaser-electrodes 2 I which may be formed as segmentspartially out from the Wall and -pressed inward as prongs. trodes arebrought closer to the anodel3 than the cathode [4, so that as thepotential of the anode increases current will flow to the teaserelectrode first, ionize the gas withinthe cell and These elec--facilitate the main discharge, which occurs between electrodes I3 and M.

The cylinder 20, 2| is one element of a condenser, the other element 31of which is provided outside the glass tube ID, as shown in Fig. 2, andis grounded. This outer element need not have any particular shape orfunction so long as it is grounded and performs as a condenser elementwith the element 20. In the case of a spark plug it may well be thegrounded metallic shell.

The gas within the tube must be of ionizable character such as nitrogen,argon, hydrogen, helium, these being merely exemplary of suitablyionizable gases. The gas is employed .at a pressure calculated inrelation to the gaps and the voltage employed to give discharge at aselected potential. For instance, a pressure of one atmosphere may beemployed with a voltage of 3,000 to 4,000, a main gap of .040 inch and ateaser gap of .010 to .015 inch. This is merely ilustrative and will bevaried according to the circumstances of use and the nature of theconstruction. The larger the surface of the tube the greater will be thecapacity of the condenser element 20. The better the contact of thecondenser element with the glass the less will be the surface of thetube required.

In Fig. 2 the tube In is shown employed in connection with a circuithaving a power line '30, a condenser 3| connected between the line andgroundon the high side of the tube, and a condenser element 31 outsidethe tube cooperating with the cylinder within it. The electrode 14 isconnected by a line 32 to a transformer 33 and a snark gap 34 operatedthereby.

The constructionof the cell can be carried out in a chamber filled withthe inert gas at appropriate pressure, but under normal circumstances itis easier to provide one of the end pieces ll, 1

H! with a small hole through which the cell can be evacuated, filledwith the selected inert gas at the selected pressure, and sealed byappropriate means such as welding, soldering, or by the employment ofa'suitable plastic.

The tubes as thus constructed are durable and areefiicient and uniformin operation and when inserted in a spark plug circuit as described in acopending application Ser. No. 627,474, filed November 8. 1945, secureuniform operation of the plugs without respect to variations inatmospheric pressure and without regard to pressure variations withinthe cylinders of an aircraft engine. The cell itself isof simpleconstruction and is adapted to mass production methods.

The-cell has the particular advantage that only one circuit is requiredfor its charging, in that only the main electrode need be connected to asource of power. Once the potential of that electrode attains a selectedvalue, a discharge will commence across the air gap to the teaserelectrode, which is itself a condenser-element. That discharge producesan ionization sufi'lcient for the current-to strike across the main gapto the electrode 1 4. Another advantage of the invention ls'in themethodof constructing the cell, particularly in the method of joining theplates to the glass body of the cell. -Other advantages :lie in ithemanifold'uses of-the'cell in'controlling discharge :in various :types ofcircuits, only one of which has been disclosed herein as-anon-limitative example,

Although only one embodiment of the invention has herein beenillustrated and described, it is to be expressly understood that thesame is not limited thereto. Various changes may be made in the designand arrangement of the parts without departing from the spirit and scopeof the invention, as will now be clear to those skilled in the art. Fora definition of the limits of the invention, reference is had primarilyto the appended claims.

What is claimed is:

1. A device for regulating electrical discharge comprising a cellcontaining ionizable gas, spaced electrodes in-said cell, and meanscomprising a condenser connected to ground having an element within thecell in closer relation to the charge thereof.

2. A device for regulating electrical discharge comprising .animper'meable dielectric tube, metal platesfixed in sealing relation tothe ends of the tube, electrodes on the plates within and spaced .fromthe Wall of the tube, a metal condenser element within the tube incloser spaced relation to one said electrode than the other saidelectrode, and an ionizable gas in said tube.

3. -A-device for regulating electrical discharge comprising a glasstube, metal plates fixed in sealingrelat'i'on'to the-ends-o'f the tube,stud electrodes on the plates within and spaced from the wall of thetube a metal cylinder comprising a condenser element within the tubefixed to the wall thereof in closer spaced relation to one saidelectrode than the other said electrode, and an ionizable gas in saidtube.

4. Adevice for regulating electrical discharge comprising a :glass tube,metal plates fixed in sealing relationito the ends of the tube, studelectrodes ZOlfithe plates within and spaced from the wall of the tubeand having durable tips spaced fromeach other, .a metal cylinder withinthe tube fixedto :the-wallthereof having teaser electrodes in :proximityto 'a said electrode, and an ionizable gas :in said tube.

-5. Ai'device for regulating electrical discharge comprisinganimpermeable dielectric tube, conductingrplates fixed irrsealingirelation to the ends of the tube, electrodes 'on the plates within andspaced from the wall ."of the tube, "a metal condenser element withinthe tube in such relation to-theelectrodes-that current tends to flow tosaid element through gas in said tube prior to the flow thereof fromelectrode to electrode, and an ionizablegas in said tube.

6. :III aspark'plug circuit-having a plug, a high tension transformer,and :a-source of low tension current. adapted to feed the transformer, adevice interposed between the said source and the transformercomprisingasealed dielectric tube having metal ends with inwardly directed spacedelectrodes ihavingi-broad and flat tips of tungsten, an ionizablegasdnsaid tube, a metal sleeve on the tubewallasurrounding the anode, and aflexible projection extending -from' the sleeve in ;proximity-zto t'heanode.

7. rl=n=a=spark :plug circuithavlng aplug, a high tensionitransformer,and a source of low tension current adapted to feed the transformenadevice interposed between the said .source and the transformercomprisinga sealed dielectric tube having metal ends with inwardly directed spacedelectrodes, an ionizable gas in said tube, a metal sleeve on the tubewall surrounding the anode but not the cathode, and a flexibleprojection extending from the sleeve in proximity to the anode.

8. Ina spark-plug circuit having a plug, a high 5 tension transformer,and a source of low tension REFERENCES CITED current adapted to feed thetiansmrmer' The following references are of record in the viceinterposed between the said source and the me of this patent:transformer comprising a sealed dielectric tube having metal ends withinwardly directed spaced 5 UNITED STATES PATENTS electrodes, anionizable gas in said tube, and a Number Name Date metal sleeve on thetube wall surrounding the 1370 077 Whisler Mat 1 192.1 anode but not thecathode, and being in closer 2027399 QStermeh. Jan. 1936 relation to theanode than to the cathode and 2197114 Rabezzana 1940 than the anode isto the cathode, and constitut- 10 2230:298 Karl 4 1941 mg Mensa gmund-2:288361 Watrous July '1, 1942 mo TOGNOLA- 2,397,982 Salzberg Apr. 19,1946 MAURICE S. THORN.

